Modern identity cards are presently manufactured as follows: an application for a document is made on a form, generally a card form, hereinafter referred to as the "Application Form", and the form includes a photograph together with information such as date of birth, address, occupation, issue and expiry dates, applicant's signature, family information, serial number, the location of an establishment, the signature of the responsible authority, etc., and this "word" information is advantageously prepared and printed on the application form by computerized machinery; once the application form has been completed, the filled-in portion (including the photograph) intended to appear on the final identity card is photographed as a whole. This zone of information to appear on the front of the final card is referred to hereafter as the "useful zone".
The negative obtained in this way is used to transfer said information onto a positive security medium, i.e. a medium which is previously prepared in such a way as to make it difficult to reproduce, e.g. by means of special weft insertions, a special chemical composition, moire type patterning, etc. The final document is then fabricated by a purely physico-chemical process without there being any risk of error, since both the negative and the positive medium are perforated to enable them to be tractor driven through the machinery.
This method does not enable information on the front of the document to be transferred to the back. In order to do this, complex document management is necessary, including storing the information to be printed on the back, turning over the document and then reproducing said information by means of a printer which is required to reproduce said information some suitable length of time after the operations on the front of the document. This gives rise to manufacturing difficulties which are particularly acute when the machinery is started, or whenever the machinery is interrupted in the middle of operation due to some technical incident or a power cut. Further, turning the document over introduces a discontinuity in the continuous manufacturing process and this is unacceptable when large numbers of documents are to be manufactured.
Further, the information to be transferred to the back of the document can only be transferred after the photographic development operations on the front of the document have been completed. Such photographic operations require the document to be passed through various baths, and there is no guarantee that prior-printed information will survive passing through such photographic baths without being damaged. Also, it has not been possible to provide photographic processing of both sides of the document simultaneously using a process which is simple enough for industrial automation.
Preferred implementations of the present invention remedy these drawbacks and provide a method and apparatus in which information is printed on the basis of reading the front of the document and synchronously with said reading, thereby avoiding any risk of error due to mismanaging the information, which is, of course, particularly advantageous when producing security documents.
The present invention seeks to transfer or copy characters or signs to the back of a document by substantially identically reproducing characters or signs appearing on the front of the document.